Democratic Northwest. [volume] (Napoleon, Ohio) 1869-1894, 1887-08-25
THE GREAT AMERICAN LAKES.
Where Do Shey Get Their Supply of
Water?-Change ofLevel.

It has long been known that the
great lakes are subject to remarkable
and seemingly capricious changes of
level. These changes are roughly
registered in the varying volume OF the
st. Lawrence-that remarkable river,
itself the outlet of these great lakes
and in a sense a continuation and o
part of the lakes themselves. In some
years the st. Lawrence, which drains a
watershed of over 900 square miles,
is much fuller all summer than in other
years. 1t leaves Lake Erie already a
broad river, forty feet deep. At the
great cataract of Niagara it descends
with its enormous mass of nearly 400,-
600 cubic feet of water in every second
of time. ..a :.
This almost incomprehensible mass
of water, the drainage or overflow OF
all the great lakes, varies in volume
with the level of the lakes of which 1t
is part. A Milwaukee paper gives
some interesting facts relating to these
mysterious irregular tidal movements,
or change oflevel in Lake Michigan.
This, the second in size and depth of
these great lakes-the largest bodies of
fresh water on the globe-is subject to
strange fluctuations; being several feet
lower in some years than in others.
Lake Michigan is deep lake, about a
thousand feet deep, or practically as
deep as Lake Superior. 1t has been, it
seems, for nearly thirty years the prac-
tice of the Government to take daily
measurements of the height of the
water at Milwaukee. The water, which
at that point las the clinging memory
of plunge into it at the close of July,
1S49, still attests) is almost as icy cold
as it is at Mackinaw, is usually foot
or two higher in summer than it is in
winter; but in some years the variation
is equal to three or four feet. This
represents, on so great body of water,
an enormous difference. Lake Superb
or alone is almost as large as the great
State of Ohio, while Lake Michigan,
the direct receiver of its overflow, is
about as large as Massachusetts, Yer
mont and New Hampshire put to-
gether. A change of three or four feel
in the level Of these great lakes implies
a difference in the amount of water toe
fgreat to be fully understood and ap
preciated. The other lakes necessarily
participate in these fluctuations; but
these appear to be most marked In
Lake Michigan.
Their cause is not yet wholly under
stood. Various theories have been ad
yanced to account for them-even t.
the absurd extent of connecting then
with the ocean tidal movements. Blu
a far simpler explanation seems more
probable. 1t would seem that thu
higher level in Lake Michigan in sum
mer and autumn may be caused by thu
spring and summer rains and the lat
melting SHOWS of the vast Canadian
watershed which feeds Lake Snperio
with its rushing streams and copiou
rivers. In that immense lake the ris'
ofa single foot is equivalent to a mucl
| greater rise in the lesser lakes of tn
Sreat system. That the fiuctuation
should be irregular, showing a ia
greater level in some years than il
others, might we'll be due to the vary
ing qualities of May and June rains II
! different years, and to the create
! quantities of snow remaining in thos
hyperborean latitudes, to be only trans
! formed in May and June, into watel
OF course the influx received by tn
: larger lake would be far less in winter
and hence the lakes would be lowest 1
, winter and highest in summer an
autumn. Whatever the cause may
the occurrence itself of these larg
: fluctuations in the level of such vas
bodies of water is one of the strikin
: facts in the worlds greatest fresh waite
: system, and well worthy ofphilosophiC
5 al examination. That lake and rive
: system-or perhaps it might be calle
! all one great river, 1000 miles LONG
: the most interesting one the globe
! Its greatest expansion-the vast LAX
!, Superior--is at a level Of over 900 fee
= = above the level of the sea a lake who's
! !, area is 81 500 square miles, and who's
: depth is 900 feet. The river flows o
J its lordly course through the rocks
the Laurentian system, the Oldest 0
!. the globe, and it receives as its aff1uer
;. ;. the dark, wild waters Of the Saguency
= : Hartford Times.
n An artesian we'll at Romeo, Mich
II filings ice water twenty-five feet high.